This application claims the benefit of German patent application 10104179.9, filed Jan. 23, 2001, herein incorporated by reference.
The invention relates to thermostatic valves, and particularly to a thermostatic valve that includes an axially open annular slide that can be displaced by means of a thermostatic operating element; a base plate that, together with an edge of the annular slide, forms a gasket seat and has a clamping edge and openings between the clamping edge and the gasket seat; a restoring spring, which biases the annular slide in the direction of the base plate; and an abutment for the restoring spring.
In typical thermostatic valves, a movable valve plate is driven by a thermostatic operating element between a closed position and an open position according to the temperature of the fluid being conveyed through the valve. Such valves provide for fairly precise control of coolant flow according to a desired operating temperature of the device, such as an internal combustion engine, which is being cooled. When a large-volume flow of coolant is required, however, known thermostatic valves present a number of disadvantages, chief among them the loss of coolant pressure because the coolant impinges upon the valve plate.
In those cases in which large volume flows of coolant are required for cooling an engine, a thermostatic valve of the type mentioned at the outset is employed in place of a thermostatic valve that operates by means of a valve plate. In such annular slide thermostatic valves, an axial coolant flow passes through the annular slide during operation, and specifically when coolant is being conveyed to a radiator. Because the coolant does not impinge upon a valve plate, the pressure loss is fairly small.
Such known thermostatic valves are typically supplied in parts and then assembled during installation in the coolant circuit of an internal combustion engine. Assembly in situ is required because the restoring spring for the annular slide and thermostatic operating element is supported on a cross arm, which is in turn supported on the housing on which the thermostatic valve is mounted. Because the parts are potentially fairly small and require precise alignment during assembly, it is desirable to have a thermostatic valve that is capable of being pre-assembled.
It is therefore an object of the present invention to provide for an improved thermostatic valve which provides for larger-volume coolant flows and is capable of being installed in a pre-assembled state.
Specifically, the present invention provides for a thermostatic valve whose restoring spring is mounted on the base plate of the valve.
Because the restoring spring is mounted on the base plate of the valve rather than on a cross arm which must be supported on the valve housing, the present invention makes it possible to pre-assemble the elements of the thermostatic valve into a component which can, in turn, be mounted between two parts of a housing or the like. In addition to reducing the costs of installation, pre-assembly of the valve makes it possible to check the seal between the annular slide and the base plate before installation.
In one embodiment of the invention, a shackle, the ends of whose legs are fastened on shoulders of the base plate, is used as the abutment for the restoring spring. It is helpful to design the shoulders of the base plate as open hooks, which engage with the ends of the legs of the shackle. This feature simplifies the pre-assembly process, because the shackle and restoring spring may be easily mounted by pushing and rotating the shackle.
In another embodiment of the invention, the shackle may be equipped with a collar, which serves to guide the housing of the thermostatic operating element. Such a collar provides a means by which the thermostatic operating element may be aligned with the shackle.
In still another embodiment of the invention, the end of the annular slide facing away from the gasket seat is provided with strips which are essentially oriented radially inward and hold a mounting, which fixes the annular slide in place on the housing of the thermostatic operating element. In this embodiment it is advantageous to design the mounting as a circumferential ring, which is supported in the axial direction on an annular shoulder of the housing of the thermostatic operating element, because the connection between the annular slide and the housing of the thermostatic operating element is thereby made easily and securely.
Further characteristics and advantages of the invention will be seen in the following description of the thermostatic valve, in accordance with the invention represented in the drawing.